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Extensions of Time (EOTs): how to claim and protect your programme

How to claim an EOT under HIA, MBA and ABIC contracts: eligible grounds, notice deadlines, documentation, and the link to liquidated damages.

By Dan Waring. Last updated 7 May 2026. Verified 7 May 2026.

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TL;DR

An Extension of Time (EOT) is a formal written claim that adds days to the contracted building period when a qualifying delay occurs beyond the builder’s control. Miss the notification window, which is typically 5 to 10 working days after becoming aware of the delay depending on the contract suite, and you may forfeit the entitlement entirely. Once granted, liquidated damages cannot run for the extended period. The biggest source of LD exposure on residential jobs is builders who experience genuine qualifying delays (weather, client variations, approvals hold-ups) but fail to document and notify in time, leaving them exposed for delays that were never their fault. Read alongside Reading a building contract: what to look for first for where the EOT clause sits in the wider commercial mechanics.

When you do this

An EOT claim is made as soon as a qualifying delay event becomes known, not after the job is already running late. The notification obligation is triggered when you become aware that works will be delayed, not when the delay has fully played out.

Submit your notice:

  • Immediately on becoming aware of the delay event, and in any case within the contract’s notification period
  • Before the contracted practical completion date (most contracts do not allow retrospective claims after that date has passed)
  • Each time a new delay event occurs, even on the same job (a separate notice per event is the safer approach)

Who’s involved

PartyRole
BuilderIdentifies the delay, prepares and serves the written notice, keeps supporting records
Owner / PrincipalReceives the notice, may dispute within the dispute window (typically 5 working days)
Architect (ABIC jobs)Assesses and determines EOT claims; acts as contract administrator
Builder’s contracts manager or adviserDrafts and checks the notice for completeness

Eligible delay grounds

The grounds differ slightly between contract suites, but the core categories are consistent across HIA, MBA and ABIC residential contracts.

HIA contracts (clause 19.1)

The following qualify as grounds for an EOT under HIA residential contracts (verified 2026-05-07 against contractsspecialist.com.au and hia.com.au):

  • Adverse weather conditions (unpredictable and severe, not run-of-the-mill wet days)
  • Delays in receiving necessary approvals or permits from authorities
  • Owner-requested variations that affect the programme
  • Unavailability of materials or labour beyond the builder’s control
  • Industrial disputes affecting trades or material supply
  • Industry shutdown periods (e.g. Christmas close) that were not reasonably foreseeable at contract signing
  • Any other event beyond the builder’s reasonable control that was not reasonably foreseeable

MBA contracts

MBA residential contracts (including the 2024 MBA ACT Lump Sum Residential Building Contract) allow EOTs for (verified 2026-05-07 against mba.org.au):

  • Civil commotion or industrial disputes affecting trades or supply
  • Any act, default or omission by the owner
  • Anything else beyond the builder’s control, including trade contractor or material shortages

ABIC SW-2018 and MW-2018

ABIC contracts are architect-administered. The architect assesses EOT claims and issues a formal determination. EOT grounds under ABIC contracts follow a similar pattern to HIA and MBA (verified 2026-05-07 against acumen.architecture.com.au).

What does NOT qualify

  • Builder’s own resource planning errors (insufficient trades booked, late ordering)
  • Wet weather that is routine and seasonally foreseeable at the time of signing
  • Delays caused by the builder’s subcontractors (these are the builder’s risk to manage upstream)
  • Variations the builder initiated

Steps

  1. Identify the delay event. Note the exact date you became aware that works would be delayed. Start the clock from that day.

  2. Assess the grounds. Is the cause listed in clause 19.1 of your contract (HIA) or equivalent? If yes, you have a potential entitlement. If uncertain, treat it as a potential EOT and document anyway.

  3. Quantify the impact. How many working days does the event affect? Tie this to the construction programme, not a rough estimate. If weather, count rain days and drying-out days against your critical path logic. If an owner variation, identify which activities are pushed out and by how many days.

  4. Prepare the written notice. The notice must contain:

    • The cause of the delay (referenced to the contract ground)
    • The date the delay event occurred or became known
    • The estimated extension period (days)
    • The revised practical completion date

  5. Serve within the notification window:

    • HIA (NSW): 10 working days after becoming aware of the delay (verified 2026-05-07 against contractsspecialist.com.au)
    • HIA (ACT): 5 working days after becoming aware (verified 2026-05-07 against hia.com.au)
    • MBA: notification requirements vary by state contract; check clause 30 or equivalent notice provision in your specific contract
    • ABIC: submit to the architect as contract administrator; confirm the timeframe in the project conditions

    Serve notice by the method prescribed in the contract (hand delivery, post, or email to the address listed in contract particulars). Verbal notice is not sufficient.

  6. Keep supporting records. The notice creates the entitlement; the records support it if disputed:

    • Daily site diary entries
    • Weather station or BOM data (for weather delays)
    • Supplier communications and delivery records (for supply delays)
    • Council or authority correspondence (for approval delays)
    • RFI logs and response dates (for design/information delays)
    • Photographs

  7. Await the owner’s response. Under HIA contracts, the owner has 5 working days to dispute the claim in writing. If no dispute is received, the extension stands. Under ABIC, the architect issues a formal determination.

  8. Adjust the programme and notify progress payments if required. A granted EOT pushes the practical completion date forward. Update your programme and reconfirm any progress claim dates that reference completion milestones. EOTs also interact with the defects liability period, which runs from the (now extended) practical completion date.

Documents needed

DocumentPurpose
Written EOT notice (signed)Creates the contractual entitlement
Updated construction programmeShows critical path impact
Site diary entriesContemporaneous evidence of delay
BOM weather data or authority recordsObjective third-party confirmation
Supplier/subcontractor correspondenceEvidences cause beyond builder’s control
PhotographsVisual record of site conditions on delay days
Copy of the owner’s response (if any)Records the agreed or disputed outcome

Common holds

  • Missing the notification window. This is the most common reason valid EOT claims fail. If you miss 10 working days under HIA NSW, you may lose the entitlement entirely, even if the delay was genuine. Set a calendar reminder the day you identify a qualifying event.

  • Vague notice. “Weather delay” without dates, programme impact, or a revised completion date is not a valid notice under most contract suites. Complete each required element.

  • Claiming after practical completion. Most contracts do not allow retrospective EOT claims once the contracted completion date has passed. Claim as events occur, not in a batch at the end of the job.

  • Owner-caused delay without an EOT claim. If the owner changes scope, is slow to provide instructions, or delays access, and the builder doesn’t claim an EOT, the builder is exposed to LDs for time the owner actually ate. This is the “prevention principle” problem: if the owner prevents timely completion but the builder can’t extend time to account for it, the contractual completion date may become unenforceable (“time at large”), but that is not a safe place to be. Claim the EOT and document the owner’s delay (verified 2026-05-07 against constructionlawmadeeasy.com).

  • Confusion about “automatic” EOTs. Under some contract suites (MBA), certain EOTs are sometimes described as “automatic.” This means the entitlement exists without formal approval from the owner, but it does not mean the notification requirement is waived. Serve notice regardless.

EOT and liquidated damages: the key relationship

Liquidated damages (LDs) are the pre-agreed daily penalty for late completion. They run from the day after the contracted practical completion date.

A successfully claimed EOT pushes that completion date forward. LDs cannot run during the extended period. If a builder fails to claim a valid EOT, LDs can accrue even for delays that were the owner’s fault or force majeure, because the contracted date never moved.

The relationship works like this:

ScenarioOutcome
Builder delays, no EOT ground, no EOT claimedLDs run from original completion date
Qualifying delay event, EOT claimed and notified correctlyCompletion date extended; no LDs for the extended period
Qualifying delay event, no notice served within windowBuilder may forfeit EOT entitlement; LDs run from original date
Owner-caused delay, builder claims EOTCompletion date extended; LDs cannot run; owner may owe delay costs
Owner-caused delay, builder does not claim EOTRisk of time at large or LDs exposure; neither is desirable

What can go wrong

  • Double-dipping weather claims. A week of rain does not automatically equal 5 EOT days if some activities can continue under shelter. Only days where the weather actually held up critical path activities count.

  • Concurrent delays. If both the builder and the owner contribute to the same delay at the same time, the outcome depends on the contract wording. Some contracts bar an EOT when the builder is concurrently in default. Get legal advice on concurrent delays before a dispute escalates.

  • LDs clause with no EOT clause. A contract that imposes LDs but gives the builder no EOT mechanism is imbalanced. If the owner then causes a delay, the builder may have no contractual mechanism to extend time, potentially triggering the prevention principle and making the LDs unenforceable. This is a contract red flag: do not sign it without fixing it.

  • Owner disputes a valid claim. If the owner disputes in writing within 5 working days, the dispute resolution clause of the contract applies. Under HIA, this typically goes to conciliation, then arbitration or tribunal. Maintain your records; they are your evidence.

  • Notice served to wrong address or wrong method. If the contract specifies the notice address and method (email to a specific address, or by post), a notice served by text message or to a different email may not be valid service. Check the contract particulars.

References

See also

Last updated: 2026-05-07. Verified: 2026-05-07. Quarterly review for currency.

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